Many conventional systems for transmitting data between components within a cabinet or between cabinets of components use copper or optical backplanes for transmission of digital data. For example, high data rate transceiver systems are utilized in many backplane environments, including optical switching devices, router systems, switches, chip-to-chip communications and storage area networking switches. Other environments that utilize high-speed communication between components include inter-cabinet communication and chip-to-chip communications. Typical separation of components in such systems is between about 0.1 to about 10 meters.
Existing techniques utilized in such environments typically use non-return to zero (NRZ) modulation to send and receive information over high-speed backplanes or for high data rate chip-to-chip interconnects. Typically, the transceiver for sending high-speed data over a backplane is called a serializer/deserializer, or SERDES, device. A typical SERDES device utilizes an equalizer to reduce the effects of distortions that are introduced in the transmission process. This equalizer can be situated at the transmitter side (referred to as “pre-emphasis”) or it can be placed at the receiving end (referred to as “receiver equalization”).
When a SERDES device is connected to the backplane, the SERDES device must be activated in order to communicate with the backplane. This is typically referred to as training the SERDES device. When training the SERDES device, information bits (i.e. training bits) are input into the SERDES and the output of the SERDES is received and analyzed for the presence of these training bits in order to determine if the SERDES is communicating properly with the backplane. This method requires that these training bits be captured reliably in order to train the equalizer. However, reliable capture of the training bits requires that the frame from which the training bits are captured by equalized. Since reliable capture requires equalization and equalization cannot occur without reliable capture, it is difficult to train the SERDES properly. Therefore, a need exists in the prior art for a method for training a SERDES that overcomes this problem.